There are two ways to count votes for the Democrats' national health care plan. The first is to tally the lawmakers who are definitely yes or leaning yes. The second is to count the ones who are definitely no and leaning no.

From the Republican side, it's the second group that matters. Just like Democrats need 216 votes to pass the bill, Republicans and their Democratic allies need 216 to stop it. I just got off the phone with a well-placed House GOP source, and the Republicans' latest count is that there are 209 votes against the bill at this moment, leaving opponents seven short of being able to defeat it. By the same count, there are 204 votes for the bill, leaving the Democratic leadership 12 short of being able to pass it. There are 18 votes thought to be undecided.

This is the way it breaks down. There are 431 members of the House, 253 Democrats and 178 Republicans. All the Republicans oppose the bill. At the moment, GOP sources believe that more than 30 -- they think it's 31 -- Democrats are opposed. Those Democrats are motivated by a variety of concerns. "It's abortion, it's cost control, it's taxes, it's Medicare, and for some of them, it's just their district," says the GOP source.

Of the 18 Democrats who are undecided, Republicans will have to win seven votes to prevail, provided Republicans do in fact have 209 votes now. The Democratic leadership would have to win over 12 undecideds, if in fact Democrats are at 204 now.

"If you're trying to win a vote like this, you never want to be in the situation where you have to get virtually everybody who's still left in the pool," says the source. "That's difficult. They have to get two-thirds, and that's a lot."

Of course, Republicans can't do much to win over the undecided Democrats. They have virtually no inside game; they can't offer lawmakers inducements or threaten to punish them like Speaker Nancy Pelosi can. But the GOP can continue to push home the message that the bill falls short on the issues mentioned above: abortion, cost control, taxes, Medicare, etc. And there are, of course, Republicans who are friends with Democrats and vice versa. While there's no overt lobbying going on, there are a lot of "What are you hearing?" conversations taking place.

Another thing Republicans are doing is keeping tabs on the pressure groups on the left. In particular, GOP staffers are watching the whip count done at the lefty website Firedoglake. (The most recent count there is 205 yes, 209 no, very close to the GOP tally.) Republicans feel it is accurate, particularly in this sense: They believe that no Democratic lawmaker who is definitely planning to vote yes on the bill would want the activists on the left, in this case exemplified by Firedoglake, to believe he or she is still undecided. Why take a beating for nothing?